The present disclosure relates to a fuel system for delivering fuel to a gas turbine engine.
A typical fuel system includes a large pump driven by a turbine engine through a gearbox. In order to achieve desired fuel volumes and pressures for the engine, the pump is specifically oversized for peak demand. As a result, the fuel system includes a bypass valve to return unneeded fuel back to the engine fuel inlet or fuel tank, which is inefficient. The fuel returned to the tank is hot, which undesirably raises the temperature of fuel in the fuel tank. Furthermore, excess pressure is generated that must be relieved by using a pressure relief valve to mitigate any potential burst or over pressure conditions.
In a multistage combustor engine, fuel injectors are arranged into operative groups called “stages”. Typically, a single engine-driven pump and metering valve feed fuel to a plurality of fuel distribution lines. Each fuel distribution line includes a staging valve for modulating fuel flow to a single combustor stage, which includes a plurality of fuel injectors. Some fuel systems additionally include temperature sensors proximate the fuel injectors to monitor temperature distribution around the combustor.